Abiotic and biotic contexts shape the effect of disturbance on non-native plant invasion

Making predictions about when and where a given mechanism of invasion will be weak or strong is crucial for the effective management of non-native species. Despite the importance of disturbance on invasion, our understanding of how variation in abiotic and/or biotic conditions may modify the disturbance-invasion relationship is scarce. Here, we aimed to evaluate how abiotic (soil type) and biotic (tree and shrub cover) contexts affect the disturbance-invasion relationship in disturbed and nearby non-disturbed communities in the semi-arid open forest of central Argentina (ca. 36° S) using field sampling. We found that abiotic context modulated non-native species success in disturbed communities, whereas both abiotic and biotic context modulated success in nearby non-disturbed communities. These findings suggest that the plant invasion-disturbance relationship is context-dependent. Our results hint at the possibility that the significance of disturbance in predicting invasion might diminish as the importance of abiotic filters increases.

精准预判某一入侵机制在何时、何地会呈现出强弱差异，对于外来物种（non-native species）的有效管理至关重要。尽管干扰（disturbance）对生物入侵的影响举足轻重，但当前学界对非生物（abiotic）与/或生物（biotic）条件的变异如何调控干扰-入侵关系的认知仍较为匮乏。本研究依托阿根廷中部（约南纬36°）半干旱开阔林的野外采样（field sampling），旨在评估非生物环境（以土壤类型为代表）与生物环境（以乔木、灌木盖度为代表）如何分别调控受干扰群落及邻近未受干扰群落中的干扰-入侵关系。研究结果显示，非生物环境可调控受干扰群落中外来物种的入侵成功率，而邻近未受干扰群落的入侵成功率则同时受非生物与生物环境的共同调控。上述发现表明，植物入侵与干扰间的关联具有情境依赖性。本研究结果还提示，随着非生物过滤（abiotic filters）效应的重要性提升，干扰在预测生物入侵过程中的作用或会有所减弱。